Simplifications and performance improvement in pager_write().
FossilOrigin-Name: ab7aeeead395a05b91a921ef9ebe9252fffad667
diff --git a/src/bitvec.c b/src/bitvec.c
index f1f347f..fd908f7 100644
--- a/src/bitvec.c
+++ b/src/bitvec.c
@@ -126,8 +126,8 @@
** If p is NULL (if the bitmap has not been created) or if
** i is out of range, then return false.
*/
-int sqlite3BitvecTest(Bitvec *p, u32 i){
- if( p==0 ) return 0;
+int sqlite3BitvecTestNotNull(Bitvec *p, u32 i){
+ assert( p!=0 );
i--;
if( i>=p->iSize ) return 0;
while( p->iDivisor ){
@@ -149,6 +149,9 @@
return 0;
}
}
+int sqlite3BitvecTest(Bitvec *p, u32 i){
+ return p!=0 && sqlite3BitvecTestNotNull(p,i);
+}
/*
** Set the i-th bit. Return 0 on success and an error code if
diff --git a/src/pager.c b/src/pager.c
index a50272d..164fd61 100644
--- a/src/pager.c
+++ b/src/pager.c
@@ -808,7 +808,7 @@
**
** if( pPager->jfd->pMethods ){ ...
*/
-#define isOpen(pFd) ((pFd)->pMethods)
+#define isOpen(pFd) ((pFd)->pMethods!=0)
/*
** Return true if this pager uses a write-ahead log instead of the usual
@@ -1031,19 +1031,21 @@
int i;
for(i=0; i<pPager->nSavepoint; i++){
p = &pPager->aSavepoint[i];
- if( p->nOrig>=pgno && 0==sqlite3BitvecTest(p->pInSavepoint, pgno) ){
+ if( p->nOrig>=pgno && 0==sqlite3BitvecTestNotNull(p->pInSavepoint, pgno) ){
return 1;
}
}
return 0;
}
+#ifdef SQLITE_DEBUG
/*
** Return true if the page is already in the journal file.
*/
static int pageInJournal(Pager *pPager, PgHdr *pPg){
return sqlite3BitvecTest(pPager->pInJournal, pPg->pgno);
}
+#endif
/*
** Read a 32-bit integer from the given file descriptor. Store the integer
@@ -5649,6 +5651,59 @@
}
/*
+** Write page pPg onto the end of the rollback journal.
+*/
+static SQLITE_NOINLINE int pagerAddPageToRollbackJournal(PgHdr *pPg){
+ Pager *pPager = pPg->pPager;
+ int rc;
+ u32 cksum;
+ char *pData2;
+ i64 iOff = pPager->journalOff;
+
+ /* We should never write to the journal file the page that
+ ** contains the database locks. The following assert verifies
+ ** that we do not. */
+ assert( pPg->pgno!=PAGER_MJ_PGNO(pPager) );
+
+ assert( pPager->journalHdr<=pPager->journalOff );
+ CODEC2(pPager, pPg->pData, pPg->pgno, 7, return SQLITE_NOMEM, pData2);
+ cksum = pager_cksum(pPager, (u8*)pData2);
+
+ /* Even if an IO or diskfull error occurs while journalling the
+ ** page in the block above, set the need-sync flag for the page.
+ ** Otherwise, when the transaction is rolled back, the logic in
+ ** playback_one_page() will think that the page needs to be restored
+ ** in the database file. And if an IO error occurs while doing so,
+ ** then corruption may follow.
+ */
+ pPg->flags |= PGHDR_NEED_SYNC;
+
+ rc = write32bits(pPager->jfd, iOff, pPg->pgno);
+ if( rc!=SQLITE_OK ) return rc;
+ rc = sqlite3OsWrite(pPager->jfd, pData2, pPager->pageSize, iOff+4);
+ if( rc!=SQLITE_OK ) return rc;
+ rc = write32bits(pPager->jfd, iOff+pPager->pageSize+4, cksum);
+ if( rc!=SQLITE_OK ) return rc;
+
+ IOTRACE(("JOUT %p %d %lld %d\n", pPager, pPg->pgno,
+ pPager->journalOff, pPager->pageSize));
+ PAGER_INCR(sqlite3_pager_writej_count);
+ PAGERTRACE(("JOURNAL %d page %d needSync=%d hash(%08x)\n",
+ PAGERID(pPager), pPg->pgno,
+ ((pPg->flags&PGHDR_NEED_SYNC)?1:0), pager_pagehash(pPg)));
+
+ pPager->journalOff += 8 + pPager->pageSize;
+ pPager->nRec++;
+ assert( pPager->pInJournal!=0 );
+ rc = sqlite3BitvecSet(pPager->pInJournal, pPg->pgno);
+ testcase( rc==SQLITE_NOMEM );
+ assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );
+ rc |= addToSavepointBitvecs(pPager, pPg->pgno);
+ assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );
+ return rc;
+}
+
+/*
** Mark a single data page as writeable. The page is written into the
** main journal or sub-journal as required. If the page is written into
** one of the journals, the corresponding bit is set in the
@@ -5658,7 +5713,6 @@
static int pager_write(PgHdr *pPg){
Pager *pPager = pPg->pPager;
int rc = SQLITE_OK;
- int inJournal;
/* This routine is not called unless a write-transaction has already
** been started. The journal file may or may not be open at this point.
@@ -5671,7 +5725,6 @@
assert( assert_pager_state(pPager) );
assert( pPager->errCode==0 );
assert( pPager->readOnly==0 );
-
CHECK_PAGE(pPg);
/* The journal file needs to be opened. Higher level routines have already
@@ -5690,91 +5743,41 @@
assert( pPager->eState>=PAGER_WRITER_CACHEMOD );
assert( assert_pager_state(pPager) );
- /* Mark the page as dirty. If the page has already been written
- ** to the journal then we can return right away.
- */
+ /* Mark the page that is about to be modified as dirty. */
sqlite3PcacheMakeDirty(pPg);
- inJournal = pageInJournal(pPager, pPg);
- if( inJournal && (pPager->nSavepoint==0 || !subjRequiresPage(pPg)) ){
- assert( !pagerUseWal(pPager) );
- }else{
-
- /* The transaction journal now exists and we have a RESERVED or an
- ** EXCLUSIVE lock on the main database file. Write the current page to
- ** the transaction journal if it is not there already.
- */
- if( !inJournal && !pagerUseWal(pPager) ){
- assert( pagerUseWal(pPager)==0 );
- if( pPg->pgno<=pPager->dbOrigSize && isOpen(pPager->jfd) ){
- u32 cksum;
- char *pData2;
- i64 iOff = pPager->journalOff;
- /* We should never write to the journal file the page that
- ** contains the database locks. The following assert verifies
- ** that we do not. */
- assert( pPg->pgno!=PAGER_MJ_PGNO(pPager) );
-
- assert( pPager->journalHdr<=pPager->journalOff );
- CODEC2(pPager, pPg->pData, pPg->pgno, 7, return SQLITE_NOMEM, pData2);
- cksum = pager_cksum(pPager, (u8*)pData2);
-
- /* Even if an IO or diskfull error occurs while journalling the
- ** page in the block above, set the need-sync flag for the page.
- ** Otherwise, when the transaction is rolled back, the logic in
- ** playback_one_page() will think that the page needs to be restored
- ** in the database file. And if an IO error occurs while doing so,
- ** then corruption may follow.
- */
- pPg->flags |= PGHDR_NEED_SYNC;
-
- rc = write32bits(pPager->jfd, iOff, pPg->pgno);
- if( rc!=SQLITE_OK ) return rc;
- rc = sqlite3OsWrite(pPager->jfd, pData2, pPager->pageSize, iOff+4);
- if( rc!=SQLITE_OK ) return rc;
- rc = write32bits(pPager->jfd, iOff+pPager->pageSize+4, cksum);
- if( rc!=SQLITE_OK ) return rc;
-
- IOTRACE(("JOUT %p %d %lld %d\n", pPager, pPg->pgno,
- pPager->journalOff, pPager->pageSize));
- PAGER_INCR(sqlite3_pager_writej_count);
- PAGERTRACE(("JOURNAL %d page %d needSync=%d hash(%08x)\n",
- PAGERID(pPager), pPg->pgno,
- ((pPg->flags&PGHDR_NEED_SYNC)?1:0), pager_pagehash(pPg)));
-
- pPager->journalOff += 8 + pPager->pageSize;
- pPager->nRec++;
- assert( pPager->pInJournal!=0 );
- rc = sqlite3BitvecSet(pPager->pInJournal, pPg->pgno);
- testcase( rc==SQLITE_NOMEM );
- assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );
- rc |= addToSavepointBitvecs(pPager, pPg->pgno);
- if( rc!=SQLITE_OK ){
- assert( rc==SQLITE_NOMEM );
- return rc;
- }
- }else{
- if( pPager->eState!=PAGER_WRITER_DBMOD ){
- pPg->flags |= PGHDR_NEED_SYNC;
- }
- PAGERTRACE(("APPEND %d page %d needSync=%d\n",
- PAGERID(pPager), pPg->pgno,
- ((pPg->flags&PGHDR_NEED_SYNC)?1:0)));
+ /* If a rollback journal is in use, them make sure the page that is about
+ ** to change is in the rollback journal, or if the page is a new page off
+ ** then end of the file, make sure it is marked as PGHDR_NEED_SYNC.
+ */
+ assert( (pPager->pInJournal!=0) == isOpen(pPager->jfd) );
+ if( pPager->pInJournal!=0 /* Journal open */
+ && sqlite3BitvecTestNotNull(pPager->pInJournal, pPg->pgno)==0 /* pPg not in jrnl */
+ ){
+ assert( pagerUseWal(pPager)==0 );
+ if( pPg->pgno<=pPager->dbOrigSize ){
+ rc = pagerAddPageToRollbackJournal(pPg);
+ if( rc!=SQLITE_OK ){
+ return rc;
}
- }
-
- /* If the statement journal is open and the page is not in it,
- ** then write the current page to the statement journal. Note that
- ** the statement journal format differs from the standard journal format
- ** in that it omits the checksums and the header.
- */
- if( pPager->nSavepoint>0 && subjRequiresPage(pPg) ){
- rc = subjournalPage(pPg);
+ }else{
+ if( pPager->eState!=PAGER_WRITER_DBMOD ){
+ pPg->flags |= PGHDR_NEED_SYNC;
+ }
+ PAGERTRACE(("APPEND %d page %d needSync=%d\n",
+ PAGERID(pPager), pPg->pgno,
+ ((pPg->flags&PGHDR_NEED_SYNC)?1:0)));
}
}
-
- /* Update the database size and return.
+
+ /* If the statement journal is open and the page is not in it,
+ ** then write the page into the statement journal.
*/
+ if( pPager->nSavepoint>0 && subjRequiresPage(pPg) ){
+ rc = subjournalPage(pPg);
+ }
+
+ /* Update the database size and return. */
if( pPager->dbSize<pPg->pgno ){
pPager->dbSize = pPg->pgno;
}
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 3ebd8de..aed6557 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -3238,6 +3238,7 @@
Bitvec *sqlite3BitvecCreate(u32);
int sqlite3BitvecTest(Bitvec*, u32);
+int sqlite3BitvecTestNotNull(Bitvec*, u32);
int sqlite3BitvecSet(Bitvec*, u32);
void sqlite3BitvecClear(Bitvec*, u32, void*);
void sqlite3BitvecDestroy(Bitvec*);